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<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  <script>
    //用于获取对象自身所有的属性
    var obj = {
      id:1,
      pname:'小米',
      price:1999,
      num:2000
    };
    var arr = Object.keys(obj);
    console.log(arr);
    arr.forEach(function(value){
      console.log(value);
    })
  </script>
</body>
</html>